Vina del Mar, Chile (Sports Network) - Playing his first singles tennis since last June, former world No. 1 great Rafael Nadal returned a winner Wednesday at the ATP World Tour's VTR Open.

The top-seeded Nadal blew past Argentine qualifier Federico Delbonis 6-3, 6-2 in 1 hour, 27 minutes on the red clay at Club Naval de Campo Las Salinas. Nadal struck four aces and was broken only once while tallying four breaks against the overmatched Delbonis.

Nadal is playing his first tennis in over seven months after being sidelined with a knee injury. The Spanish superstar, who owns 11 Grand Slam titles, including a record seven French Open championships in the Open Era, is appearing in a South American tournament for the first time since 2005, when he won a title in Brazil as an 18-year-old.

The 26-year-old Nadal will meet a fellow Spaniard in the quarterfinals -- either seventh-seeded Daniel Gimeno-Traver or Albert Montanes.

The current world No. 5 Nadal was a doubles winner alongside Juan Monaco here on Tuesday.

Meanwhile, Nadal's doubles partner and the defending Vina del Mar champion Monaco was stunned by Frenchman Guillaume Rufin, 7-6 (7-3), 6-4, in a second- rounder on Wednesday. The second-seeded Monaco, like Nadal, received an opening-round bye this week.

Monaco beat fellow Argentine Carlos Berlocq in last year's Vina del Mar finale and was also a runner-up at this tournament in 2008 and 2010.

An eighth-seeded Berlocq avoided a second-round upset by holding off Colombian Santiago Giraldo 7-5, 4-6, 6-4 on Day 3. Giraldo was the runner-up at this event in Santiago two years ago.

Berlocq will face the upstart Rufin in the quarterfinals.

In first-round action on Wednesday, fifth-seeded Spaniard Albert Ramos tackled Brazilian Rogerio Dutra Silva 6-4, 6-1, sixth-seeded Paolo Lorenzi leveled qualifier and fellow Italian Gianluca Naso 6-1, 6-4, and the aforementioned Gimeno-Traver got past Portuguese Joao Sousa 6-4, 4-6, 6-1.

This week's winner will collect $74,000.

The Sports Network